【作者】 朱睿；

【导师】 顾洪恩；

【作者基本信息】 天津大学 ， 材料物理与化学， 2010， 硕士

【摘要】 利用电注入方法首次对天然方解石晶体成功着色,在着色晶体产生多种色心。对着色晶体进行光谱测量和系统光谱分析,提出色心产生和转化机理。借助绘得电流-时间曲线,对色心产生过程和机理作进一步阐述.用点阴极电注入方解石晶体,在晶体中产生F （Ca⁺）和V （CO₃^-）色心、Pb²⁺和Mn²⁺杂质色心和未知色心。在不同电注入条件下,在着色晶体中产生色心种类和强度不同。通过对比不同电压、温度和时间条件下天然方解石晶体电注入吸收谱,得到方解石晶体电注入着色最有效条件为温度480℃、1200 V电压和注入时间270 min。提出天然方解石晶体电注入着色机理。该机理不同于以往其它晶体电注入着色机理。此研究结果不仅拓宽电注入晶体范围,而且丰富了电注入着色机理。在进行电注入时,记录电流和时间数据,并据此绘制出电流～时间关系曲线。经分析后推知,天然方解石晶体电注入过程历经两个过程。第一过程是第二碱土阴极的形成,第二过程是大幅着色开始至整个晶体着色完成。第一过程对应电流～时间曲线｜区,第二过程对应电流～时间曲线‖区。｜区电流主要由Mn²⁺和Pb²⁺杂质离子、Ca²⁺和CO₃^2-组分离子、Ca⁺和CO₃^-离子运动和及其CO₃^2-与石墨阳极阵列间交换电子形成。‖区电流主要由电子、Mn²⁺和Pb²⁺杂质离子、Ca²⁺和CO₃^2-组分离子、Ca⁺和CO₃^-离子运动及其CO₃^2-与石墨阳极间交换电子运动形成。其中以电子运动电流为主,因为电注入使晶体内电子过剩。通过电流～时间曲线分析,进一步解释和验证所提出天然方解石晶体电注入着色机理.点阳极电注入的天然方解石晶体中产生F （Ca⁺）和V （CO₃^-）色心、Pb²⁺和Mn²⁺杂质色心和未知色心。天然方解石晶体点阳极电注入注入过程仍与电流～时间曲线变化相对应。电流变化规律与点阴极相似,着色机理也相同。与用点阴极电注入主要不同之处在于,此处所用阳极只是一个点阳极,而不是石墨阳极阵列。天然方解石晶体点阳极电注入的研究有助于更好地理解方解石晶体电注入着色机理。对比不同条件下点阳极电注入结果,得到天然方解石晶体点阳极电注入着色最有效条件:温度505℃、3000 V电压和注入时间160 min。对比点阴极和点阳极电注入结果,得到天然方解石晶体电注入着色最有效条件为点阴极温度480℃、1200 V电压和注入时间270 min。更多还原

【Abstract】 Natural calcite crystals are successfully colored electrolytically at the first time. Several kinds of color centers are produced in colored crystals. Absorption spectra of the colored calcite crystals are measured and analyzed systematically. Mechanism of production and transformation of color centers is given. By means of measured current - time curve.The process and mechanism of color centers are explained further.F （Ca⁺）、V （CO₃^-）、Pb²⁺、Mn²⁺ impurity and unknown color centers are produced electrolytically in colored calcite crystals by using a pointed cathode. Different kinds and intensities of color centers are produced under different conditions. The most effective condition, at temperature 480 oC, voltage 1200 V and electrolysis time 270 min, of the electrolytic coloration of the natural calcite crystal is gained by contrasting to the absorption spectra of the electrolytically colored calcite crystals at different voltage, temperature and time. Mechanism of electrolytic coloration of natural calcite crystals is given. This mechanism is different from the previous mechanisms of the other crystals. This research result not only expands the range of electrolytically colored crystals, but also enriches the previous mechanisms of the electrolytic colorations.Data of current and time are recorded in the process of electrolysis, with which current - time curve is plotted. After analyzing the curve, it is known that that the electrolytic coloration of the natural calcite crystal undergoes two processes. The first one is the formation of the secondary alkaline earth cathode and the second one marks the beginning of the massive coloration and maintains the coloration. The former corresponds to the first zone of the current-time curve and the latter to the other zones. The first-zone current mainly consists of the motions of Mn²⁺, Pb²⁺impurity ions, Ca²⁺, CO₃^2- constituent ions, Ca⁺, CO₃^-ions and the electron exchanges between the CO₃^2- radicals and graphite anode matrix. The second-zone current mainly consists of the electron transport, motion of Mn²⁺, Pb²⁺ impurity ions, Ca²⁺, CO₃^2- constituent ions, Ca⁺, CO₃^- ions and electron exchanges between the CO₃^2- radicals and graphite anode matrix. The electron transport is dominant in the second-zone current. This is because the electrolysis results in the electron excess in the crystals. By analysis of the curve of current - time, the mechanism of the electrolytic colorations of the natural calcite crystals is further explained and verified.F （Ca⁺）, V （CO₃^-） color centers and Pb²⁺, Mn²⁺ impurity color centers and unknown color centers are produced electrolytically in colored calcite crystals by using a pointed anode. The change regulation of the curve of the current - time and coloration mechanism by using a pointed anode are similar with those by using a pointed cathode and. The main difference between the electrolytic colorations by using the pointed anode and the pointed cathode is that herein there is only one pointed anode and does not a graphite anode matrix. This research of the electrolytic coloration of the natural calcite crystals by using a pointed anode is favorable to understanding further the mechanism of the electrolytic colorations of the natural calcite crystals. The most effective condition, at temperature 505 oC, voltage 3000 V and electrolysis time 160 min, of the electrolytic coloration of the natural calcite crystal is gained by contrasting to the absorption spectra of the electrolytically colored calcite crystals at different voltage, temperature and time.The most effective condition, at temperature 480 oC, voltage 1200 V and electrolysis time 270 min, of the electrolytic coloration of the natural calcite crystal is gained by contrasting to the absorption spectra of the electrolytically colored calcite crystals at different voltage, temperature and time by using a pointed cathode and by using the pointed anode .更多还原